从外部将值传递给AutoMapper Type Converter

Question

我有一个多语言数据库,它根据键和枚举返回值Language.当我将DB对象转换为模型时,我希望模型包含基于键和当前语言的翻译值.

密钥来自DB对象,但如何将当前语言传递给Mapper.Map()函数？

目前,我正在使用一个[ThreadStatic]属性在调用之前设置文化Mapper.Map<>,并在中检索它TypeConverter.

public enum Language
{
    English, French, Italian, Maltese
}

public class MultilingualValue<T>
{
    public Dictionary<Language, T> Value { get; set; }
    public MultilingualValue()
    {
        this.Value = new Dictionary<Language, T>();
    }
}

public class PersonData
{
    public string FirstName { get; set; }
    public MultilingualValue<string> City { get; set; }
}

public void MapPerson()
{
    PersonData personData = new PersonData();
    personData.FirstName = "John";
    personData.City = new MultilingualValue<string>();
    personData.City.Value[ Language.English] = "The Zurrieq";
    personData.City.Value[Language.French] = "Le Zurrieque";

    MultilingualValueData.CurrentLanguage = Language.English; 

    var personModel = Mapper.Map<PersonData, PersonModel>(personData);
}

public class MultilingualValueToBasicDataTypeConverter<T> : ITypeConverter<MultilingualValue<T>, T> 
{
    public T Convert(ResolutionContext context)
    {
        var currentLanguage = MultilingualValueData.CurrentLanguage; //THIS IS THE [ThreadStatic] VARIABLE
        if (currentLanguage == null) throw new InvalidOperationException("Please make sure to fill in CurrentLanguage");

        MultilingualValue<T> sourceMultilingualValue = (MultilingualValue < T > )context.SourceValue;

        T destinationValue = default(T);
        if (sourceMultilingualValue != null)
        {
            destinationValue = sourceMultilingualValue.Value[currentLanguage.Value];
        }

        return destinationValue;
    }
}        

public static class MultilingualValueData
{
    [ThreadStatic]
    public static Language? CurrentLanguage;
}

我省略了配置,因为我认为这个例子是不必要的.如果你需要它们,我也会发布它们.

虽然这有效,但我发现这种解决方法非常难看.有没有办法通过数据传递数据ResolutionContext？

Answer 1

只需使用需要的Map重载Action<IMappingOperationOptions>.您可以将Items属性中的配置元素添加到您的属性中ITypeConverter

public class CustomConverter : ITypeConverter<string, string>
{
    public string Convert(ResolutionContext context)
    {
        return "translated in " + context.Options.Items["language"];
    }
}

internal class Program
{
    private static void Main(string[] args)
    {
        AutoMapper.Mapper.CreateMap<string, string>().ConvertUsing<CustomConverter>();
        var result = AutoMapper.Mapper.Map<string, string>("value" , opt => opt.Items["language"] = "english");
        Console.Write(result); // prints "translated in english"
        Console.ReadLine();
    }
}